About 75 percent of Americans complain about foot pain. And poorly fitting shoes are the cause in most cases.

Here are some common foot problems, their cause, and treatment:

Corns and calluses--These are the most common skin conditions of the foot. A corn is actually a form of a callus. A corn usually occurs on the tops of toes, especially the little toe, while a callus is found on the bottom of the foot. Treatment includes soaking the foot in warm water until the hardened skin softens and then using a pumice stone or callus file over the area, says Linda Clavert, RN, University of Iowa Department of Orthopaedics. Rub a small amount of olive oil directly into the callus to soften it. Over-the-counter remedies are often effective. Don't cut or trim corns yourself. If you are diabetic or have circulation problems, contact your health care provider.

Bunions--Poorly fitting shoes and heredity are the primary causes of bunions, an unsightly bump of bone on the side of the big toe joint. When it appears on the little toe bone it is know as a bunionette or a tailor's bunion. Calvert says treatment includes wearing wider, softer shoes that decrease pressure on the bunion. Avoid high-heeled, pointed-toe shoes that put enormous pressure on the front of the foot and cause the foot and toes to rest at unnatural angles. Contact your health care provider for more aggressive bunion treatments.

Ingrown toenails--Improperly trimmed toenails and tight shoes cause ingrown toenails. An ingrown toenail occurs when the edge of the toenail grows into the soft skin surrounding the nail. Always cut toenails straight across, leaving them a little longer at the corners. Treatment includes soaking the toe in warm water, pressing a small amount of wet cotton under the nail, forcing the nail to grow over the top of the skin. Continue packing until the nail grows out. Don't try to "dig" out the nail at home.

Many adult foot problems can be traced to wearing the wrong shoes during childhood and teen years. The shape of the shoe should fit the natural shape of the foot. After your child has worn a new pair of shoes for a while, examine your child's bare feet for signs of redness or irritation. Check the fit of your child's shoe. Not all problems are caused by the shoe.

Here's what to look for when buying shoes so your child's feet grow into healthy adult feet. These rules also apply to anyone buying shoes.

• Shoes should be held on the foot with laces, straps, or Velcro. Avoid slip-on shoes.
• Flat shoes are best for children.
• Choose shoes with leather uppers. Synthetics like nylon, plastic, and rubber don't allow the sweat to escape properly and increase the chances of athlete's foot and toenail problems.
• Try shoes on both feet and buy the size that best fits the larger foot.
• Try on shoes wearing the same type of socks you will wear with the shoes.
• Don't buy a shoe that you hope will "stretch out."
• The toe of the shoe should allow the toes to move freely and not be squashed at the top or the sides.
• Fashion shoes are fine for special occasions, but "foot friendly" shoes are best for regular wear.

When standing in a sports shoe, there should always be one thumb's breadth between the end of the shoe and the longest toe.